A flexible display is a display device based on a flexible base. Flexible display device has broad application prospects and good market potential due to its features such as rollability, wide viewing angle, and carriability. At present, the materials used for the flexible display base are ultra-thin glass, plastic film, metal foil, and the like.
Polyimide (PI) is a kind of polymer with imide repeating units, which has the advantages of wide application temperature, chemical resistance, high strength, and high insulation. PI has been widely used as a special engineering material in aviation, aerospace, microelectronics, and other fields. At present, PI as a flexible substrate material has been successfully applied to some flexible display electronics.
Flexible display substrate is not only a major difficulty but also a key technology of a flexible OLED display device. The stability of flexible display substrate in the back-end process is conducive to greatly improve the yield of the array, the bending property of the flexible display device mainly depends on the design of the flexible substrate, including the material of the flexible substrate and the structure of the flexible substrate, and how to ensure the stability of the back-end process is a problem to be solved.